Liquid crystal display and method of manufacture

Abstract

An active matrix type liquid crystal display composed of a liquid crystal cell 124 is described. In the liquid crystal cell 124, liquid crystals at the upper and lower interfaces of a liquid crystal layer 122 inserted between an array substrate 106 having pixel electrodes 128 and an opposed substrate 105 having an opposed electrode 127 have pretilt angles opposite to each other in a positive/negative sense and are aligned in parallel with each other, forming a spray alignment. This liquid crystal display performs displaying by bend-aligning such a liquid crystal cell 124. The pixel electrodes 128 are formed on a flattening film 100 for covering switching elements 123 or wiring electrodes flat. With this arrangement, a spray to bend alignment transition can be reliably, easily caused in a short time within the liquid crystal cell pixels, so that an OCB mode liquid crystal display free from alignment defects and having high picture quality can be achieved.

What is claimed is:  
     
       1. A liquid crystal display which comprise a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates; 
       wherein where the alignment state of a liquid crystal when no voltage is applied to the liquid crystal layer is defined as an alignment state  1  and the alignment state of the liquid crystal used for performing displaying is defined as an alignment state  2 , the alignment state  1  differs from the alignment state  2 ;  
       wherein the alignment state  1  is a splay alignment state whereas the alignment state  2  is a bend alignment state;  
       wherein source wiring electrodes, gate wiring electrodes, and switching elements are disposed on one of the substrates;  
       wherein a flattening film is stacked on the switching elements;  
       wherein pixel electrodes electrically connected to the switching elements are disposed on the flattening film; and  
       wherein in plan view, the pixel electrodes overlap with the source wiring electrodes or the gate wiring electrodes.  
     
     
       2. A liquid crystal display according to  claim 1 , wherein in plan view, the pixel electrodes overlap with the source wiring electrodes and the gate wiring electrodes. 
     
     
       3. A liquid crystal display according to  claim 1 , wherein the flattening film is composed of a resin layer. 
     
     
       4. A liquid crystal display according to  claim 1 , wherein irregularities are provided on the flattening film, and the level difference of the irregularities are 1 μm or less. 
     
     
       5. A liquid crystal display according to  claim 4 , wherein the level differences of the irregularities are 0.5 μm or less. 
     
     
       6. A liquid crystal display according to  claim 1 , wherein the spacing between the pixel electrodes is within the range of from 1 μm to 10 μm. 
     
     
       7. A liquid crystal display according to  claim 1 , wherein one of the substrates has a plurality of pixel electrodes and the spacing between the pixel electrodes is within the range of from 1 μm to 5 μm. 
     
     
       8. A liquid crystal display which comprises a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates; 
       wherein where the alignment state of a liquid crystal when no voltage is applied to the liquid crystal layer is defined as an alignment state  1  and the alignment state of the liquid crystal used for performing displaying is defined as an alignment state  2 , the alignment state  1  differs from the alignment state  2 ;  
       wherein source wiring electrodes, gate wiring electrodes, and switching elements are disposed on one of the substrates;  
       wherein a flattening film is stacked on the switching elements;  
       wherein pixel electrodes electrically connected to the switching elements are disposed on the flattening film;  
       wherein in plan view, the pixel electrodes overlap with the source wiring electrodes or the gate wiring electrodes;  
       wherein the spacing between the pixel electrodes is within the range of from 1 μm to 10 μm; and  
       wherein at least part of the pixel electrodes is higher than the average height of the pixel electrodes.  
     
     
       9. A liquid crystal display which comprises a pair of substrates and a liquid crystal layer sandwiched between the pair of substrates; 
       wherein where the alignment state of a liquid crystal when no voltage is applied to the liquid crystal layer is defined as an alignment state  1  and the alignment state of the liquid crystal used for performing displaying is defined as an alignment state  2 , the alignment state  1  differs from the alignment state  2 ;  
       wherein source wiring electrodes, gate wiring electrodes, and switching elements are disposed on one of the substrates;  
       wherein a flattening film is stacked on the switching elements;  
       wherein pixel electrodes electrically connected to the switching elements are disposed on the flattening film;  
       wherein in plan view, the pixel electrodes overlap with the source wiring electrodes or the gate wiring electrodes;  
       wherein the spacing between the pixel electrodes is within the range of from 1 μm to 10 μm; and  
       wherein a voltage is applied across the pixel electrodes and an opposed electrode formed on the other one of the pair of substrates, thereby transiting the alignment state of the liquid crystal layer to a bend alignment to perform displaying in the condition after the transition.